Climate change threat to wildlife

Some of Britain's rarest wildlife will become extinct within 50 years as climate change takes hold, while other species take advantage of the warmth and move north to colonise new areas, according to a new study.

In the largest such exercise undertaken in any country in the world, 16 of the UK's biggest government and private conservation groups have studied 50 species to see how they would fare in the increased temperatures and changed rainfall patterns currently predicted for Britain.

The south and east will become too hot and dry for some species, like the beech tree and natterjack toad, which will migrate north. Some birds, like the snow bunting, finding that lack of cold a problem, will have nowhere left to go.

English Nature, the National Trust, and the environment agency, together with their Scottish and Northern Ireland partners - and national organisations including the Royal Society for the Protection of Birds - used computer modelling and observation to track the "winners" and "losers".

Some birds and butterflies are already on the move in response to climate change. The nuthatch is moving north and west and could reach as far as the outer Hebrides by 2050. By that time it may be forced to retreat from the south-east of England, where it currently thrives, because it will be too hot and dry.

But one of the difficulties in making predictions in such a crowded island, with motorways and built up areas blocking the way, is in understanding how some species can migrate at all.

A bird often moves hundreds of miles to find new feeding grounds, but plants and trees find adapting to new conditions much harder.

Other potential bird "winners" include the nightingale, willow tit, yellow wagtail and turtle dove - but this depends on suitable habitat to encourage species to move.

One suggestion from English Nature is to provide protected wildlife corridors where there is enough space for species to migrate naturally. This would certainly help insects and animals, but might be too slow for most plants.

For rarities with specialised habitats like the natterjack toad, these measures may not be good enough. This amphibian lives in south-east England, Merseyside and Cumbria. It relies on temporary pools to breed, but studies show these will dry out too quickly because of temperature rise by 2020, although by 2050 new habitat will emerge further north. The trick will be to move the toad to new grounds at the right time.

Wales will lose several plant species because it will be warmer, but they will survive in Scotland.

Rising sea levels will cause widespread flooding of coastal habitats. The fate of many wading birds depends on how humans react to these changes. Curlews, dunlins and redshanks will all lose feeding grounds and reduce in numbers unless estuaries are allowed to enlarge and new wetlands created.

The work, funded by the government as part of the UK climate impacts programme, stresses that it is not just increased temperatures but changes in rainfall and more extreme weather events which also affect the ability of wildlife to survive. There will be an increase in winter rainfall everywhere, but it will be 22% drier in the south in the summer by 2050.

Higher evaporation rates in the heat of summer will seriously affect the ability of some tree and plant species to survive in the south, but bog and marsh plants may do better in the north. Sea levels will rise by up to 78cm (31in) in the south and east by mid-century, requiring careful management for flood prevention and to save wildlife.

Losers by 2050

Mountain ringlet butterfly (Erebia epiphron) is set to become extinct. It lives in mountains in the Lake District and Scotland but as temperatures warm its "climate space" entirely disappears from Britain. The survey says no conservation effort can save it.

Beech trees (Fagus sylvatica) are drought sensitive because of shallow roots, and are expected to die back as soils become drier in the summer. The species is expected to disappear in East Anglia and southern England. In theory it could survive further north, but tree migration is slow.

Oyster catcher (Haematopus ostralegus) Some estuaries and wet habitats near the sea are expected to increase because of more winter rainfall and sea level rise, helping the food supply of these distinctive and noisy birds.

Azure damselfly (Coenagrion puella). Warmer conditions suit most insects and warmer wetter conditions in the north mean this insect will spread from England and Wales to Scotland and Northern Ireland.

Marsh gentian (Gentiana pneumonanthe) More rain in the north is likely to waterlog former dry heath, providing new habitat for this plant. Some areas in the south may dry out, but overall the species is expected to benefit.